JPH0244056B2 - KANKOSEIJUSHISOSEIBUTSU - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photosensitive resin composition. More specifically, the present invention relates to a photosensitive resin composition for forming a protective film that has excellent properties that can be used in printed wiring board production, metal precision processing, and the like.

It is well known that photosensitive resin compositions are used to form resists for plating or etching in the precision processing industry, for example, in the manufacture of printed wiring boards. Recently, photosensitive resin compositions have also been used in the field of permanent masks such as electroless plating masks and solder masks.

Permanent masks are heat resistant, solvent resistant, chemical resistant,
Since excellent properties such as electrical properties and mechanical properties are required, there are a limited number of photosensitive resins that can be used. JP-A-52-117985, JP-A-54-1018, JP-A-53-56018, etc. disclose photosensitive resin compositions that can be used as permanent masks. However, these photosensitive resin compositions mainly contain a polymer binder and a monomer and are not suitable for forming a thick protective film. That is, since these photosensitive resin compositions use a polymeric binder with a high glass transition temperature, when forming a photosensitive layer, the photosensitive resin composition is first mixed with toluene, methyl ethyl ketone, or chloride. It must be uniformly dissolved or dispersed in an organic solvent such as methylene, then coated and dried to form a photosensitive layer. Therefore, when the film becomes thick, air bubbles are likely to occur during drying and the resin tends to flow, making it difficult to form a uniform protective film.

On the other hand, Japanese Patent Application Laid-Open No. 53-13696 discloses that it has excellent heat resistance and adhesion, and can be used as a solder mask.
UV-curable solvent-free liquid resin compositions have been proposed.

This liquid composition comprises at least one compound having at least two radically polymerizable unsaturated groups and the following formula [] [In the formula, Z is a cyclic dibasic acid residue, R ¹ is a carbon number of 1 to
3 alkylene group, R ² is a hydrogen atom or a methyl group,
X is a chlorine atom or a bromine atom. ], and an image can be formed by screen printing. Regarding this composition, it is also possible to apply a photographic method, in which case, Japanese Patent Publication No. 46-39404, Japanese Patent Publication No. 48-23284,
A liquid photosensitive layer of a certain thickness is formed on a substrate using a coating apparatus such as that disclosed in Japanese Patent Application Laid-Open No. 49-43701, and a precise image can be formed by imagewise irradiation with active light and development. However, JP-A-53-13696
The liquid resin composition disclosed in the publication leaves room for improvement in the electrical insulation properties, electrolytic corrosion resistance, etc. of the cured film.

In view of these facts, the present inventors conducted various studies and found that when the compound described in JP-A-53-13696 is used in combination with a compound having at least one epoxy group, the electrical insulation and dielectric strength are improved. It has been found that a cured film with excellent edibility and resolution can be obtained.

The purpose of the present invention is to facilitate the formation of a thick protective film;
Another object of the present invention is to provide a photosensitive resin composition that has excellent properties such as resolution, adhesion to metals, electrical insulation, and electrolytic corrosion resistance.

The present invention provides (a) at least one photopolymerizable compound having at least two terminal ethylene groups, and (b) a compound represented by the formula [where Z is a cyclic dibasic acid residue and R ¹ is Alkylene group having 1 to 3 carbon atoms, R ²
is a hydrogen atom or a methyl group, and X is a chlorine atom or a bromine atom. ], (c) at least one compound having an epoxy group, and (d) a sensitizer or (and) a sensitizer system that generates free radicals when exposed to actinic rays. relating to things.

Each of the components constituting the photosensitive resin composition proposed by the present invention will be explained in detail below.

The photosensitive resin composition of the present invention contains as an essential component at least one photopolymerizable compound having at least two terminal ethylene groups. Suitable compounds include acrylic esters and methacrylic esters of polyhydric alcohols, including trimethylolpropane, trimethylolethane, pentaerythritol, 1,3-butylene glycol, 1,4-butylene glycol, and 1,6-butylene glycol. hexanediol, propylene glycol, tripropylene glycol, polypropylene glycol,
ethylene glycol, polyethylene glycol,
Neopentyl glycol, dibromneopentyl glycol, bihydric alcohol obtained by reacting two phenolic hydroxyl groups of bisphenol A with 1 to 10 ethylene oxides, propylene to two phenolic hydroxyl groups of bisphenol A. 2 obtained by reacting 1 to 10 oxides each
Examples include acrylic acid, ester, and methacrylic acid ester of polyhydric alcohols such as dihydric alcohols obtained by reacting 1 to 10 propylene oxides with two phenolic hydroxyl groups of tetrabromo bisphenol A. obtain.

Also, cycloaliphatic epoxy resin, novolak type epoxy resin, bisphenol A type epoxy resin,
A reaction product of a compound having at least two epoxy groups such as methacrylic acid or methacrylic acid, and (a) diisocyanate, (b) acrylic acid monoester or methacrylic acid monoester of dihydric alcohol, and optionally ( c) Urethane diacrylate compounds or urethane dimethacrylate compounds obtained by reacting dihydric alcohols can also be used. Specific examples of urethane diacrylate compounds and urethane dimethacrylate compounds include trimethylhexamethylene diisocyanate/2
-Hydroxyethyl acrylate reactant, trimethylhexamethylene diisocyanate/cyclohexanedimethanol/2-hydroxyethyl acrylate reactant, trimethylhexamethylene diisocyanate/2-hydroxypropyl acrylate reactant, trimethylhexamethylene diisocyanate/2- Hydroxyethyl methacrylate reactant, trimethylhexamethylene diisocyanate/2-hydroxypropyl methacrylate reactant, hexamethylene diisocyanate/2-hydroxypropyl methacrylate reactant, isophorone diisocyanate/2-hydroxyethyl acrylate reactant, isophorone diisocyanate/2-hydroxyethyl acrylate reactant, Isocyanate/2-hydroxyethyl methacrylate reaction product, 2,6 diisocyanate methyl caproate/
2-hydroxyethyl acrylate reactant, 2,
Examples include methyl 6 diisocyanate caproate/2-hydroxyethyl methacrylate reaction product.

The second essential component of the present invention is a compound represented by the above formula []. The compound represented by the formula [] is disclosed in Japanese Patent Publication No. 53-37214,
For example, it can be easily produced from a cyclic dibasic acid anhydride by the reaction represented by the following formula (wherein Z, R ¹ , R ² , and X are the same as those defined in formula ()). ).

Formula (a) Formula (b) Examples of cyclic dibasic acid anhydrides include succinic anhydride, phthalic anhydride, hexahydrophthalic anhydride,
Tetrahydrophthalic anhydride, hymic anhydride (3,6 endomethylene 1,2, manufactured by Hitachi Chemical Co., Ltd.)
Examples include (trade name of 3,6 tetrahydrophthalic anhydride) methylhymic anhydride (trade name of 3,6 endomethylene 1,2,3,6 tetrahydromethyl phthalic anhydride manufactured by Hitachi Chemical Co., Ltd.).

The compound represented by the formula [] is a monovalent acrylic ester or methacrylic ester containing a chlorohydrin group or a bromohydrin group, and a liquid photosensitive resin composition containing this compound has excellent resolution. .

The photosensitive resin composition used in the present invention contains as an essential component a compound having at least one epoxy group. This epoxy group-containing compound is used to capture hydrogen halide generated from the compound represented by the formula [] by light irradiation, heat treatment, etc., to prevent a cured film, and to protect metals from corrosion. Examples of compounds having at least one epoxy group include phenyl glycidyl ether, p-butylphenol glycidyl ether, cresyl glycidyl ether,
Acrylicidyl ether, glycidyl methacrylate, octylene oxide, diglycidyl ether of bisphenol A, bisphenol A type epoxy resin, ring type epoxy resin manufactured by Chitsuso Corporation (Chissonox 206, Chissonox 221, Chissonox 201, etc.), Daicel Chemical Industries, Ltd. Examples include ring type epoxy resin Celoxide 2021 manufactured by ).

The photosensitive resin composition used in the present invention contains as an essential component a sensitizer or (and) a sensitizer system that generates free radicals by actinic light. Sensitizers that can be used include substituted or unsubstituted polynuclear quinones, such as 2-ethylanthraquinone, 2
-t-butylanthraquinone, octamethylanthraquinone, 1,2-penzanthraquinone,
2,3-diphenylanthraquinone etc., ketoaldonyl compounds such as diacetyl and benzyl, α-ketaldonyl alcohols and ethers such as benzoin and pivalone, α-hydrocarbon substituted aromatic acyloins such as α-phenyl-benzoin, Examples include aromatic ketones such as α,α-diethoxyacetophenone, benzophenone, and 4,4′-bisdialkylaminobenzophenone, which may be used alone or in combination. Examples of sensitizer systems that can be used include combinations of 2,4,5-lyarylimidazole dimer and 2-mercaptobenzoquinazole, leuco crystal violet, tris(4-diethylamino-2-methylphenyl)methane, etc. can. Additionally, additives can be used which do not have photoinitiating properties by themselves, but which, when used in combination with the above-mentioned substances, result in a sensitizer system with better photoinitiating performance as a whole. Examples include tertiary amines such as triethanolamine for benzophenone. These sensitizers or (and) sensitizer systems are the above-mentioned (a) photopolymerizable compounds,
The content is preferably 0.5 to 10% by weight based on (b) the compound represented by formula [] and (c) the compound having an epoxy group.

20 to 90 parts by weight of at least one photopolymerizable compound having at least two terminal ethylene groups, 40 parts by weight of at least one compound represented by formula []
~5 parts by weight 40 to 5 parts by weight of at least one compound having at least one epoxy group and 1 to 10 parts by weight of a sensitizer or (and) a sensitizer system that generates free radicals upon actinic light. In terms of photopolymerizability, resolution, adhesion of the cured product, etc., it is preferable to set it within this range.

In addition to the above-mentioned essential components, the photosensitive resin composition of the present invention can contain secondary components for various purposes. Examples of the subsidiary components include thermal polymerization inhibitors, dyes, pigments, antifoaming agents, flame retardants, plasticizers, adhesion improvers, and latent curing agents for epoxy resins. Selection of these secondary components is made based on the same considerations as those for ordinary photosensitive resin compositions.

The photosensitive resin composition of the present invention can be used to form a protective film using a conventional method. For example, the photosensitive resin composition of the present invention is homogenized by stirring and mixing at room temperature to 150°C, and then applied to a thickness of 10 to 300 μm on a substrate to be processed and protected. A protective film can be formed by image-wise irradiation to cure the exposed areas, and then elution of the unexposed areas by development. In order to prevent the photosensitive layer from adhering to the negative film, it is also possible to interpose a transparent cover film such as polyethylene terephthalate film, polypropylene film, cellulose acetate film, polycarbonate film, etc. between the negative film and the photosensitive layer. .
When obtaining a high-resolution protective film, the thickness of the cover film is desirably 25 μm or less.

The type of developer used in the development process is not particularly limited as long as it does not damage the exposed areas and selectively elutes the unexposed areas. Examples of the developer include halogenated hydrocarbons such as 1,1,1-trichloroethane, organic solvents such as diethylene glycol monobutyl ether/sodium carbonate aqueous solution/dilute aqueous alkali solution, and the like.

The image-like protective film obtained by the above method serves as a corrosion-resistant film for ordinary etching, plating, etc.
After development, exposure to actinic light and heat treatment at 80°C to 200°C result in a protective film with even better properties. The order of exposure to actinic light and heat treatment after development may be in any order. The protective coating thus obtained is sufficiently resistant to organic solvents such as tricrene, methyl ethyl ketone, isopropyl alcohol, and toluene, and also resistant to acidic or alkaline aqueous solutions. Furthermore, since it has excellent heat resistance and mechanical properties, it can be used as a permanent protective film for solder masks and the like. Furthermore, since the film formed using the photosensitive resin composition of the present invention has excellent chemical and physical properties, it can be used as an interlayer insulating layer of a multilayer printed wiring board,
It is also used in photosensitive adhesives, paints, plastic reliefs, printing plate materials, etc.

Next, examples of the present invention will be shown. The examples shown here are illustrative of embodiments of the present invention, and the present invention is not limited thereto.

In the examples, "parts" indicate parts by weight.

Example 1 Trimethylhexamethylene diisocyanate 1
Urethane diacrylate compound obtained by reacting 2 moles of 2-hydroxyethyl acrylate with 80 parts of phthalic anhydride, 2-hydroxyethyl methacrylate, and epichlorohydrin Compound represented by the formula []... 15 parts Celoxide 2021 (alicyclic epoxy resin manufactured by Daicel Chemical Industries, Ltd.)...5 parts Benzophenone...2.7 parts Michler's ketone...0.3 parts p-methoxyphenol...0.1 part The above formulation has a viscosity of approximately 30 poise (at 25℃) ) was prepared, applied to a thickness of 80 μm on a 1 mm thick stainless steel plate, and irradiated with 150 mJ/cm ² through a negative mask using an ultra-high pressure mercury lamp Phoenix 3000 manufactured by Oak Seisakusho. Exposure. After leaving for 30 minutes, 18
Spray developed for 30 seconds at °C. After development, the film was dried by heating at 80° C. for 10 minutes, and irradiated at 25 J/cm ² using an ultraviolet irradiation device manufactured by Toshiba Electric Materials Corporation. Thereafter, it was heat-treated at 150°C for 30 minutes. A cured film with a precise image shape corresponding to a negative mask was obtained. This film showed no change after being immersed in trichlene, toluene, isopropanol, and 10% sulfuric acid aqueous solutions at 25°C for 1 hour, and also withstood soldering at 26°C for 10 seconds, causing no cracks or cracks on the copper foil. No peeling was observed, indicating that it could be used as a solder mask.

Example 2 The photosensitive resin composition of Example 1 was manufactured by Hitachi Chemical Co., Ltd.
Copper-clad laminate MCL-E-67 (single-sided plate, plate thickness 1.6 mm,
It was applied to a thickness of about 100 μm on a comb-shaped electrode (line width 200 μm, line spacing 300 μm) prepared by etching copper foil (35 μm thick). Next, the ultraviolet irradiation device manufactured by Toshiba Electric Materials Co., Ltd. (rated voltage 200V, rated power consumption)
7.2KW, compatible lamp H5600L/2, number of lamps 1
) and irradiated at 50 J/cm ² . Then 150℃
The mixture was heat-treated for 30 minutes. The comb-shaped electrode treated in this way was exposed to 40℃ and 90%RH for 20 days.
Although a DC voltage of 100 V was applied, no discoloration was observed on the electrode. For comparison, a photosensitive resin composition obtained by removing Celoxide 2021 from the photosensitive resin composition of Example 1 was subjected to the same treatment, and discoloration occurred on the anode within 3 days of voltage application. This indicates that the photosensitive resin composition of the present invention has superior electrolytic corrosion resistance and reliability as a permanent protective film compared to the photosensitive resin composition disclosed in JP-A-53-13696. It will be done.

Example 3 Trimethylhexamethylene diisocyanate 1
Mol and 2-hydroxypropyl acrylate 2
Urethane diacrylate compound obtained by reacting with molar...75 parts Compound of formula [] used in Example 1 synthesized from phthalic anhydride, 2-hydroxyethyl acrylate, and epichlorohydrin...20 parts Epicote 828 (Ciel (Bisphenol A type epoxy resin)...5 parts Benzophenone...2.7 parts Michler's ketone...0.3 part p-methoxyphenol...0.1 part Victoria Pure Blue...0.02 part The above formulation has a viscosity of approximately 30 poise (25℃) A photosensitive resin composition was prepared and applied onto a copper-clad laminate provided with a spacer (thickness: 160 μm) to keep the thickness of the photosensitive layer constant. A polyethylene terephthalate film (thickness: 4 μm) and a negative mask (transparent line width: 30 μm, line spacing: 300 μm) were overlaid on the surface of this photosensitive layer.
Irradiation was performed at 300 mJ/cm ² using an ultra-high pressure mercury lamp Phoenix 3000 manufactured by Oak Seisakusho. After being left to stand for 30 minutes after exposure, spray development was carried out using 1,1,1-trichloroethane at 18° C. for 30 seconds. After development, 40℃
The sample was dried by heating for 10 minutes, and then irradiated with 50 J/cm ² using an ultraviolet irradiation device manufactured by Toshiba Denzai. Then 1 at 150℃
Heat treated for hours. The resulting protective coating has a thickness
It had a resolution of 160 μm and a line width of 40 μm, and had excellent properties such as trichlene resistance, electrical insulation, and heat resistance, and could be used as a permanent protective coating.

Example 4 Trimethylhexamethylene diisocyanate/
Cyclohexane dimethanol/2-hydroxyethyl acrylate (1/0.1/1.9 molar ratio) reaction product...80 parts Compound of formula [] used in Example 1 synthesized from phthalic anhydride, 2-hydroxyethyl acrylate, and epichlorohydrin... ...10 parts Epolite 1600 (hydrogenated bisphenol A type epoxy resin manufactured by Kyoeisha Yushi Kagaku Kogyo Co., Ltd.) ...10 parts Benzophenone ...2.9 parts Michler's ketone ...0.1 part p-methoxyphenol ...0.1 part Victoria Pure Blue ... ...0.02 part A photosensitive resin composition having a viscosity of about 70 poise (25°C) was prepared using the above formulation, and an excellent permanent protective coating was obtained in the same manner as in Example 1.

Example 5 Aronix M6200 (oligoester acrylate manufactured by Toagosei Chemical Industry Co., Ltd.) ...50 parts Aronix M8060 (oligoester acrylate manufactured by Toagosei Chemical Industry Co., Ltd.) ...10 parts phthalic anhydride, 2-hydroxyethyl acrylate , compound of formula [] synthesized from epichlorohydrin......20 parts Araldite ECN1235 (novolac type epoxy resin manufactured by Ciba)......20 parts 2-ethylanthraquinone...3 parts p-methoxyphenol...0.1 part Victoria Pure Blue... ...0.02 part A photosensitive resin composition having a viscosity of 70 poise (25°C) was prepared using the above formulation, and an excellent permanent protective coating was obtained in the same manner as in Example 1.

Example 6 Aronix M6100 (oligoester acrylate manufactured by Toagosei Kagaku Kogyo Co., Ltd.)...40 parts Trimethylolpropane acrylate...20 parts Used in Example 1 synthesized from phthalic anhydride, 2-hydroxyethyl acrylate, and epichlorohydrin Compound of formula []...10 parts Araldite ECN1280 (Novolac type epoxy resin manufactured by Ciba Corporation)...30 parts Benzophenone...2.7 parts Michler's ketone...0.3 parts p-methoxyphenol...0.1 part Victoria Pure Blue...0.02 parts A photosensitive resin composition having a viscosity of about 100 poise (35° C.) was prepared using the above formulation, and an excellent permanent protective coating was obtained in the same manner as in Example 1.

Claims (1)

[Scope of Claims] 1 (a) At least one photopolymerizable compound having at least two terminal ethylene groups (b) A compound represented by the formula [] [wherein Z is a cyclic dibasic acid residue, R ¹ is an alkylene group having 1 to 3 carbon atoms, R ² is a hydrogen atom or a methyl group, and X is a chlorine atom or a bromine atom. (c) at least one compound having an epoxy group; and (d) a sensitizer or (and) a sensitizer system that generates free radicals when exposed to actinic rays. . 2 (a) 20 to 90 parts by weight of at least one photopolymerizable compound having at least two terminal ethylene groups, (b) 40 to 5 parts by weight of a compound represented by formula [], and (c) having an epoxy group. The photosensitive resin composition according to claim 1, wherein at least one of the compounds is contained in an amount of 40 to 5 parts by weight. 3. The photopolymerizable compound having at least two terminal ethylene groups is (a) trimethylhexamethylene diisocyanate, (b) acrylic acid monoester or methacrylic acid monoester of dihydric alcohol, and optionally (c) dihydric alcohol. The photosensitive resin composition according to claim 1 or 2, which is a urethane diacrylate compound or a urethane dimethacrylate compound obtained by reacting.